Organic fibers have been impregnated with organopolysiloxanes containing condensable groups to improve crease resistance and dimensional stability. U.S. Pat. No. 4,098,701 to Burrill et al, for example, discloses treating organic fibers with a composition containing (A) an organopolysiloxane having diorganosiloxane units in which the two organic radicals are monovalent hydrocarbon radicals and further contains at least two monovalent SiC-bonded organic radicals having a basic nitrogen group per molecule, (B) an organopolysiloxane having at least three silicon-bonded hydrogen atoms per molecule and (C) a catalyst which promotes the condensation of Si-bonded condensable groups. U.S. Pat. No. 4,436,856 to Huhn et al discloses a process for impregnating organic fibers with an aqueous emulsion comprising (A) an organopolysiloxane containing diorganosiloxane units in which both organic radicals are monovalent hydrocarbon radicals and also contains at least two monovalent SiC-bonded organic radicals per molecule having a basic nitrogen atom, in which the SiC-bonded organic radicals containing the basic nitrogen atom are present in monoorganosiloxane units, (B) an organopolysiloxane having at least 3 Si-bonded hydrogen atoms per molecule, (C) a catalyst which promotes the condensation of Si-bonded condensable groups, (D) an emulsifier and (E) a diorganopolysiloxane containing an Si-bonded hydroxyl group in each of its terminal units and whose organic radicals are free of basic nitrogen atoms.
The above cited Burrill patent does not disclose any siloxane units having a basic nitrogen group, other than the diorganosiloxane units and in the Huhn patent, all the SiC-bonded radicals having basic nitrogen are present in the monoorganosiloxane units. Thus, neither the Burrill patent nor the Huhn patent disclose a method for impregnating organic fibers with a composition containing an organopolysiloxane, in which the SiC-bonded radicals containing a basic nitrogen group are present in both the monoorganosiloxane units and the diorganosiloxane units.
Therefore, it is an object of the present invention to provide a method for impregnating organic fibers. Another object of the present invention is to provide a method for impregnating organic fibers which imparts to the fibers a high degree of softness and a pleasant hand. Another object of the present invention is to provide a method for impregnating organic fibers which imparts to the fibers elasticity, recovery properties and resistance to shrinkage. A further object of the present invention is to provide a method for impregnating organic fibers which imparts to the fibers excellent sewing properties. A still further object of the present invention is to provide a method for impregnating organic fibers which will retain the above properties even after they have been cleaned with water or organic solvents.